Die locking



Jv F. MUELLER Nov. 5, 1968 DIE LOCKING Filed Sept. 30, 1966 FIGS 5 II lllllllll llll INVENTOR. JOSEPH F. MUELLER FIG.2

ATTORNEYS United States Fatent D 3,408,924 DIE LOCKING Joseph F. Mueller, Dedham, Mass. (490 Centre St., Quincy, Mass. 02169) Filed Sept. 30, 1966, Ser. No. 583,216 12 Claims. (Cl. 10035) ABSTRACT OF THE DISCLOSURE A base has a threaded opening for accommodating a locking screw that passes through an eccentric opening in a generally circular cam formed with two other openings separated from the eccentric opening by a diameter of the cam. A tool is formedwith two projections that fit into the latter openings and a rotatable shaft that fits in the, locking screw so' that rotating the tool with the shaft in the locking screw first causes the cam to lock the die in position as the cam rotates about the eccentric axis against the die and then locks the cam into the locking position as the locking screw is tightened. Reverse rotation of the tool results in rapid release of the die as the locking screw is first loosened and then the cam rotated away from the die about the eccentric axis.

The present invention relates in general to methods and means for locking dies in a fixed position with adjustment potential for use in printing, embossing and die cutting presses. Apparatus and techniques according to the invention result in the provision of an adjustable locking dev'ice'th'at firmly and securely locks a die in position with a simple adjusting technique and facilitates rapid removal of the die when desired.

Apparatus according to the invention comprises means defining a die contacting or gripping surface characterized by a relatively high coefiicient of friction and forming an acute angle with the die bed when seated on the bed. Camming means is pivotable about an eccentric axis corresponding to the axis of a locking means, such as a screw, for urging the die contacting surfaceagainst the die. The die base is formed with an opening for acmommodating the locking means, this opening typically being tapped. The camming means is formed with cam gripping means'for receiving mating wrench gripping means from a locking wrench means. The locking wrench means includes an eccentric rotatable element adapted for seating in the locking means while the wrench gripping means engages the mating camgripping means so that rotation of the rotatable element substantially simultaneously tightens the locking means and urges the die contacting surface tightly against the die to be locked.

According to one aspect of the invention the die contacting surface and the camming means is a single element pivotable about the axis of the locking means. According to another aspect of the invention they are separate. elements.

Typical prior art methods utilize a die locking device comprising a screw pin technique employing side thrust action. Not only are these typical prior art methods disadvantageous from the standpoint of the time and effort requiredto efiect locking, but'typical devices tend to delaminate and crack plastic and Fiberglas dies of the type frequently in use.

Accordingly, it is an important object of this invention to provide improved methods and means for locking dies in fixed position in printing, embossing and die cutting presses. I I

It is a further object of the invention to achieve the preceding object while providing adjustment potential.

It is a further object of 'the invention to achieve the preceding objects with a device that is easily and rapidly adjustable to secure a die in place.

3,408,924 Patented Nov. 5, 1968 ice It is still another object of the inventionto achieve the preceding objects with adevice that also facilitates easy removal of the die when desired. A i

It is still a further object of the invention'to achieve the preceding objects with a tool that is relatively inexpensive and easy to fabricate and easy' to use by unskilled personnel.

Numerous other features, objects and advantages of the invention will become apparent from the following specification when read in connection with the accompanying drawings in which:

FIG. 1 is an exploded perspective view of a'device according to the invention in which a single unitary element functions as the camming means and the die gripping surface below the locking screw about which the element pivots; V

FIG. 2 is a perspective view of the device inFIG. 1 shown securing a corner of a die in place on a die bed;

FIG.'3 is a view through section 33 of FIG. 2;

FIG. 4 is an exploded perspective view of another embodiment of a locking device according to the invention in which the gripping surface and camming means comprise two elements;

FIG. 5 is a perspective view of the device of FIG. 4 seated on a die bed and holding a corner of a die in place showing the novel tool for tightening devices according to the invention; and

FIG. 6 is a perspective view through section 6-6 of FIG. 5.

With reference now to the drawing and more particularly FIG. 1 thereof, there is shown an exploded perspective view of a locking device according to the invention comprising a circular disc 11 having a knurled rim 12 that slopes inward toward the disc center from top to bottom so that the rim surface 12 may apply pressure to a die that is directed radially outward and downward to keep the die in position. Disc 11 is formed with two circular openings 13 and 14 disposed along a line that is parallel to and on the right side of a diameter of disc 11. Openings 13 and 14 are adapted to receive mating studs from a tool according to the invention shown in FIG. 5 and described below. Disc 11 is also formed with a countersunk opening 15 for receiving a set screw 16. The countersunk opening 15 is separated from a line joining centers of openings 13 and 14 by the diameter parallel to the latter line of disc 11. Countersunk locking screw 16is formed with a hexagonal opening 17 symmetrical about the locking screw axis for receiving a mating hexagonal shaft of a tightening tool according to the invention shown in FIG. 5 and described below.

Referring to FIGS. 2 and 3, FIG. 2 is a perspective view of the device of FIG. 1 in position locking the corner of a die 21 positioned on the die base 22. FIG. 3 is a sectional view through section 3-3 of FIG. 2 and shows how die base plate is formed with a tapped opening 23 for receiving the threaded end of locking screw 16.

In an actual installation, there may be two, three, four or more devices according to the invention for keeping a single die in place. One technique for securing die 21 into position is to lay it on the base 22 in the desired position. tighten each locking screw 16 partially so that each disc 11 is pivotable about the axis of an associated locking screw 16, rotating each disc 11 about the axis of the associated locking screw 16 until each such disc bears firmly against die 21 and fully tightening locking screw 16 of each disc 11. The tool described below and shown in FIG. 5 permits this to be done in substantially one operation.

With reference now to FIG. 4, there is shown still another embodiment of the invention in which the camming means and mean defining a die gripping surface comprise 3 1 two elements to achieve the advantages of the device of FIGS. 1-3 while affording the additional advantages of a larger die gripping surface in contact with the die and a means for adjusting the physical position of the locking means with great precision. To this end a base element 24 is formed with generally vertical knurled surfaces 25 and 26 that slope outward from the lengthwise midline of base plate 24 in a bottom-to-top direction for applying pressure that is directed inward and downward upon a die locked inplace thereby. Base 24 is also formed with a slot 27 having opposed arcuate ends 31 and 32 of radius conforming substantially to that of the circular bottom stud 33 of circular disc 34. The diameter of disc 34 corresponds substantially to that between the inner walls 35 and 36. The thickness of circular stud 33 is slightly less than the thickness of the base plate.

Disc 34 is formed with two openings 37 and 38 for receiving mating studs from the wrench shown in FIG. 5 and described below. Disc 34 is also formed with a circular opening 40 for receiving locking screw 41 formed with a hexagonal opening 42 for receiving a mating hexagonal shaft from the tool shown in FIG, 5 and described below.

Referring to FIG. 5, there is shown the device of FIG. 4 locking a corner of die 21. A novel tool 43 is shown above the disc 34. The tool 43 comprises a cylindrical housing 44, which may comprise a piece of pipe capped at the bottom end 45 and the top end 46. Each of the discs capping ends 45 and 46 is formed with openings coaxial with each other but eccentric with respect to housing 44 for accommodating at the upper end the circular rod 51 and at the lower end the hexagonal end 52 in which rod 51 terminates for mating with the hexagonal openings 17 and 42 of locking screws 16 and 14, respectively. The lower edge of the outside wall of cylinder 44 is formed with studs 53 and 54 for mating with openings 37 and 38, respectively, in disc 44 and openings 13 and 14, respectively, in disc 11. The upper end of rod 51 is horizontally bored to accommodate a handle rod 55. Rod 51 and its hexagonal end 52 are rotatable about the rod axis and slidable along this axis.

In operation the cylinder 44 may be grasped in the left hand and handle 55 in the right hand while seating hexagonal end 52 in hexagonal opening 42 and studs 53 and 54 in openings 37 and 38, respectively. The left hand may rotate cylinder 44 until disc 34 positions base 24 so that it holds die 21 in the desired position. Then rod 51 may be rotated to tighten the assembly into this desired position. To remove the die the tool 43 is similarly positioned and rod 51 rotated counterclockwise with the right hand to loosen the assembly. Then the left hand may rotate cylinder 44 to free the die gripping surface from the die.

If desired the edge of disc 34 may include one or more radial calibration markings and the top surface 56 may include one or more index markings for precisely positioning the surface 25 and, hence, the die 21. Such precise positioning should preferably occur when stud 33 is in contact with one of arcuate walls 31 and 32. The slot 27 permits some adjustment of surface 25 along a direction generally parallel to the length of slot 27.

There has been described novel apparatus and techniques for effecting the locking of dies rapidly, easily, precisely and with relatively low cost equipment while facilitating easy removal. It is apparent that those skilled in the art may now make numerous modifications and uses of and departures from the specific embodiments described herein without departing from the inventive concepts. Consequently, the invention is to be construed as embracing each and every novel feature and novel combination of features present in or possessed by the apparatus and techniques herein disclosed and limited solely by the spirit and scope of the appended claims.

The embodiments of the invention in which an exclu- Cit sive property or privilege is claimed are defined as follows:

1. Apparatus for looking a die seated upon a bed comprising,

means defining a die contacting surface forming an acute angle with said bed when seated upon said bed, camming means for pivotal movement about an eccentric axis generally perpendicular to said bed for urging said die contacting surface against said die, and locking means embracing said eccentric axis for urging said camming means toward said bed and maintaining said camming means in fixed relationship to said bed when said die contacting surface firmly contacts said die, said camming means being generally circular and formed with a pair of engageable means separated by a diameter of said camming means passing through said eccentric axis and joined by a line that is spaced from the latter axis and generally perpendicular to the latter diameter, said locking means comprising screwable means, whereby said screwable means may receive a screwing element and said pair of engageable means may each receive a mating pair of engaging elements so that the screwing element may function both for rotating said screwable means and as an axle about which said pair of engaging elements rotate to selectively position said camming means. 2. Apparatus for locking a die in accordance with claim 1 wherein said screwable means comprises a screw with a head for being screwed in a tapped opening in said bed formed for receiving said screwing element,

and said pair of engageable means comprise a pair of recesses for receiving a pair of mating studs comprising said engaging elements. 3. Apparatus for locking a die in accordance with claim 2 and further comprising,

said bed, said die, said bed being formed with a tapped opening embracing said eccentric axis, said die being formed with a contacted surface forming an obtuse angle with said bed that is the supplement of said acute angle which contacted surface is contacted by said die contacting surface. 4. Apparatus for locking a die in accordance with claim 3 wherein said die contacting surface is knurled.

5. Apparatus for locking 2. die in accordance with claim 2 wherein said die contacting surface is knurled.

6. Apparatus for locking a die in accordance with claim 1 wherein the circumferential surface of said camming means comprises said die contacting surface.

7. Apparatus for locking a die in accordance with claim 1 wherein said means defining a die contacting surface comprises a base plate formed with a slot for accommodating said camming means and at least one upwardly extending wall having an outer surface comprising said die contacting surface and an inner wall engaging said camming means,

said camming means being formed with a lower circu lar portion of reduced diameter corresponding substantially to the width of said slot. 8. Apparatus for locking a die in accordance with claim 1 and further comprising a tool for locking and unlocking the die of claim 1 comprising,

said screwing element, said pair of engaging elements, means defining a casing supporting said pair of engaging elements in fixed relative relationship and rotatable about the axis of said screwing element, the triangle perpendicular to said screwing element axis and defined by a point on said screwing element axis and a pair of points embraced by respective ones of said engaging elements being congruent with the triangle perpendicular to said eccentric axis and defined by a point on said eccentric axis and a pair of points embraced by respective ones of said engageable means.

9. A method of locking a die upon a bed with the apparatus of claim 8 which method includes the steps of,

securing said screwable means to said bed to restrict said camming means substantially to rotation about said eccentric axis,

positioning said screwing element in said screwable means and said engaging elements in said engageable means,

and rotating said handle to move said die contacting surface in firm engagement with said die and tighten said screwable means to maintain said camming means, said die contacting surface and said bed in fixed relative relationship.

10. A tool for locking and unlocking the die of claim 1 comprising,

said screwing element,

said pair of engaging elements,

means defining a casing supporting said pair of engaging elements in fixed relative relationship and rotatable about the axis of said screwing element,

the triangle perpendicular to said screwing element axis and defined by a point on said screwing element axis and a pair of points embraced by respective ones of said engaging elements being congruent with the triangle perpendicular to said eccentric axis and defined by a point on said eccentric axis and a pair of points embraced by respective ones of said engageable means.

11. A tool in accordance with claim 10 wherein said casing comprises a cylinder having top and bottom end plates each formed with oif axes openings through which said screwing element passes,

the bottom of said said cylinder having said engaging elements,

said cylinder being rotatable about and slideable along said screwing element,

and handle means at the upper end of said screwing element.

12. A method of locking a die upon a bed with the apparatus of claim 1 which method includes the steps of,

securing said locking means to said bed to restrict said camming means substantially to rotation about said eccentric axis,

rotating said camming means about said eccentric axis until said die contacting surface firmly engages said die,

and tightening said locking means to maintain said camming means, said die contacting surface and said bed in fixed relative relationship.

References Cited UNITED STATES PATENTS BILLY I. WILHITE, Primary Examiner. 

